Note: Descriptions are shown in the official language in which they were submitted.
CA 02559395 2010-11-12
DEVICE FOR THE MUTUAL POSITIONING OF LONGITUDINAL
BUILDING COMPONENTS
The invention relates to a device for the mutual positioning of
longitudinal building components.
Such devices are suitable, in particular, as fastening means for
racks, stands, rod constructions, three-dimensional frame constructions, as
well as
for surgical fixation devices.
The EP-B 0 700 664 discloses a device, for which four separate
jaws, mounted on a shaft, define two openings, into which fastening rods or
bone
pins' can be introduced against the force of a spiral spring positioned
between the
pair of jaws. The large number of individual parts and their slight
flexibility or
adaptability to the geometry of the building components, which are to be
introduced into the openings, is a disadvantage of this known device.
The US patent 5,727,899 of DOBROVOLNY discloses a device
with two clamps, which, however, are not intended for an external fixator.
Admittedly, this known device enables a longitudinal carrier to be snapped in
latterlly, however, only into one of the two clamps. However, this snapping in
does not take place due to the elastic deformation of the clamp, nor does it
take
place against the pressure of a spring, which is disposed between the two
clamps.
Instead, this snapping in requires a separate spring, which is disposed in the
opening of the clamp. The transitions (fulcri), which act as pivot joints, are
mounted between the openings of the clamps and the fastening ends, so that,
when
the fastening ends are expanded by means of the lever 90, the clamp openings
close, clamping the longitudinal carrier located therein. For this purpose,
the
clamps have an H shape. The fulcri are between the openings of the clamp and
the
fastening ends. The following are further disadvantages of this known device:
= a large number of individual parts
= a complicated and expensive installation
1
CA 02559395 2010-11-12
= complicated and difficult cleaning
and only rods of a certain diameter can be accommodated.
The US 2002/0151892 of WALULIK et al. discloses a generic device. A first
embodiment relates to two-piece clamps and a second embodiment relates to
elastically
deformable clamps, which are constructed in one piece and in such a manner,
that they can be
pressed together completely coaxially with the central shaft. For this
purpose, the clamps are
positioned without clearance on the central shaft.
The invention is to provide a remedy here. It is an object of the invention to
provide a device for the mutual positioning of the longitudinal building
components, which
can be constructed simply from a minimum number of individual parts and is
very flexible
with regard to the building components, which are to be accommodated and
positioned
opposite to one another.
In accordance with one aspect of the present invention, there is provided a
device for a mutual positioning of building components, which comprises two
clamps, which
can be rotated with respect to one another about an axis of rotation, A) each
of the two
clamps comprising at least two clamp limbs, B) the at least two clamp limbs in
each case
defining a clamp opening between said clamp limbs, C) the clamp opening
alternatively
being constrictable or expandable, so that a longitudinal building component,
introduced into
the clamp opening, can be pre-fixed, D) both of the two clamps having a
borehole, which is
coaxial with the axis of rotation and traverses the clamp limbs, E) the two
clamps being
mounted on a shaft and F) blocking means being provided, by means of which the
rotatability
of the two clamps about the axis of rotation alternatively can be blocked and
which are
suitable for pressing the clamp limbs of each of the two clamps against a
longitudinal
building component, which has been introduced into the clamp opening,
characterized in that
G) at least one of the two clamps is constructed S-shaped and defines two
diametrically
opposite clamp openings.
In another aspect of the present invention there is provided a clamp for a
device for the mutual positioning of longitudinal building components,
characterized in that
A) the clamp is constructed S-shaped, so that three clamp limbs and two
diametrically
opposite clamp openings are defined for accommodating longitudinal building
components,
B) the clamp openings alternatively being constrictable or expandable by an
elastic formation
2
CA 02559395 2010-11-12
of the clamp, C) the clamp having a borehole, which is coaxial with an axis of
rotation and
traverses the three clamp limbs and D) the clamp being mountable on a shaft by
means of its
borehole.
The advantages, achieved by the invention, are to be seen essentially therein
that, due to the S-shaped configuration of at least one of the two clamps, on
the one hand
cumbersome individual jaws may be omitted and, on the other, a separate,
spiral spring,
which may jam between the two jaws, becomes unnecessary. In addition, in
comparison to
the prior art, the invention construction permits greater flexibility with
respect to the building
components, which are to be accommodated in the clamp opening and the diameter
of which
may vary within a larger range. With that, it is possible, with a single
device, to position a
large number of differently dimensioned building components against one
another whereas,
in a case of the prior art, the building component and the fastening device
2a
CA 02559395 2006-09-11
must be matched to one another, so that a plurality of differently dimensioned
fastening devices is necessary, in order to be able to manage all application
cases.
For a special embodiment, at least one of the two clamps has one or
more boreholes, which extend parallel to the axis of rotation and in which
locking-
in-position pins can be moved parallel to the axis of rotation. These locking-
in-
position pins make it impossible for the clamp openings to be closed only to
such
an extent that, as a result, the diametrically opposite clamp openings would
not be
opened once again.
For a further embodiment, the borehole in the two clamps at least
partially has a diameter, which is larger than the shaft. By these means,
individual
clamp limbs can be tilted relative to the shaft, in order to narrow or expand
the
clamp opening in this way.
In the case of a further embodiment, the clamp limbs are connected
in such a manner with one another, that a pliers-like opening and closing of
the
clamp limbs can be realized about a fulcrum.
Preferably, the clamp is constructed in one piece. The advantages
over a 2-piece version lie therein that fewer individual parts are required
and that a
separate spring element is not necessary, since the clamp is self-springy.
In the case of a further embodiment, the clamp opening has a
constriction. As a result, the clamp opening, which is constricted at the
outside,
can be expanded in one step against the elasticity of the clamp with a
longitudinal
building component, such as a rod, a longitudinal carrier or a screw, so that
the
buil ing component can be introduced laterally into the clamp opening. Due to
the lasticity of the clamp, the clamp opening, which is expanded on the
inside,
then closes automatically about the building component that has been
introduced
and guarantees a primary preliminary fixing of the building component in the
clamp opening. In a second step, both clamps can be fixed simultaneously and
3
CA 02559395 2006-09-11
definitively against one another and with the building component pre-fixed
therein.
In the case of a further embodiment, the clamp opening expands
towards the outside. With that, the longitudinal building components can be
pressed more easily into the clamp opening against the elasticity of the
clamp.
For a further embodiment, the clamp openings are constructed
channel-like and have a channel axis. At least one of the clamp openings has a
cross sectional surface, which is orthogonal to its channel axis and the
boundary of
which has several circular arcs of different diameter, which are disposed one
behind the other at the adjoining clamp limbs. The advantage of this
construction
lies therein that rods of different external diameters can be clamped fast in
these
clamp openings.
For a further embodiment, the mutually adjacent clamp limbs of the
two clamps comprise a conical elevation and a conical depression respectively,
which engage one another and are coaxial with the axis of rotation. By these
means, the two conical elements are pressed into one another when the device
is
blocked, so that, due to the therefrom resulting wedging, rotation about the
axis of
rotation of the two clamps relative to one another can be prevented.
Preferably,
the surfaces of the conical elevation and/or of the conical depression are
roughened, in order to achieve an intensification therewith of the wedging of
the
two conical elements preventing the relative rotation of the two clamps.
Instead of
the roughening, denticulations or conical denticulations at the face surfaces,
which
can engage one another, are also possible.
In the case of a further embodiment, the shaft in the borehole has
clearance, so that an inclination of the clamp limbs with respect to the axis
of
rotation is not prevented during the clamping of rods by the shaft.
4
CA 02559395 2006-09-11
For a further embodiment, the borehole, at its outer outlets,
comprises borehole segments, each of which has a concave, spherical zone-like
surface, which is concentric with the axis of rotation. Preferably, the shaft
has a
head of larger diameter with a convex spherical zone-shaped surface, which is
complementary to the concave, spherical zone-shaped surface of the borehole
segments.
For a further embodiment, the blocking means have an intermediate
piece with a convex, spherical zone-shaped surface, which is complementary to
the concave, spherical zone-shaped surface of the borehole segments. With
that, it
is possible to compensate for the obliqueness between the shaft and the
borehole.
The invention and further developments of the invention are
explained in even greater detail in the following by means of the partly
diagrammatic representations of several examples, of which
Fig. 1 shows a perspective view of an inventive device,
Fig. 2 shows a side view of the device of Fig. 1 and
Figs. 3 shows a longitudinal section through a modified, inventive device.
In Figs. 1 to 3, an embodiment is shown, which comprises two
clamps 1, which can be rotated against one another about an axis of rotation
6. A
borehole 4, which is suitable for accommodating a shaft 7, which can be
connected with the blocking means 8, passes coaxially with the axis of
rotation
through the two clamps 1, which can be bought into contact with one another
axially. The diameter of the borehole 4 and that of the shaft 7 are such that
the
shaft 7 has clearance in the borehole 4.
The upper clamp 1 a is S-shaped and has three clamp limbs 2, which
are disposed transversely to the axis of rotation 6 and of which the axially
outer
CA 02559395 2006-09-11
clamp limb 2a and the middle clamp limb 2c, as well as the inner clamp limb
2b,
which is adjacent to the lower clamp lb and the middle clamp limb 2c each have
an in-between clamp opening 3a; 3b for accommodating a rod 20. The clamp
openings 3a; 3b are constructed in the form of channels and have parallel
channel
axes 22a; 22b, which are orthogonal to the axis of rotation 6.
The lower clamp, lb comprises an axially exterior clamp limb 2d as
well as an interior clamp limb 2e, which is adjacent to the upper clamp la.
The
lower clamp lb has only one clamp opening 3c between the clamp limbs 2d; 2e.
This clamp opening 3c also forms a channel, which is suitable for
accommodating
a rod 20 and has a channel axis 22c, which is orthogonal to the axis of
rotation 6.
Each of the clamp openings 3a; 3b; 3c can be expanded or
constricted by the elastic deformation of the corresponding clamp la; lb. The
elasticity of the clamp limbs 2 is attained by constructing the longitudinal
bridges
13 of the clamps 1, which held the two clamp limbs 2 together, appropriately
thin.
Moreover, each clamp opening 3a; 3b; 3c has a constriction 10 at its opening,
which is remote from the axis of rotation 6. Peripherally, the clamp openings
3a;
3b; 3c are provided with expansions 11 to facilitate the introduction of a rod
20
into the clamp opening 3a; 3b; 3c in question.
As shown in Fig. 2, the shaft 7 has at its first end 14 an outer thread
16, over which a nut 17 can be screwed as blocking means 8. At its second end
15, the shaft 7 has been provided with a head 18, which has a larger diameter
and
rests on the outer clamp limb 2d of the lower clamp lb. As it is tightened,
the nut
17 is pressed against the outer surface of the outer clamp limb 2a of the
first clamp
la, while the head 18 at the second end 15 of the shaft 7 is pressed against
the
outer surface of the outer clamp limb 2d of the lower clamp lb. One of the
clamp
openings 3b in the upper clamp la has a cross sectional surface, which is
orthogonal to its channel axis 22b and the boundary of which at each of the
clamp
limbs 2a; 2c has three circular arcs 19 with different diameters, so that
circularly
6
CA 02559395 2006-09-11
cylindrical rods 20 with different diameters can be accommodated in this clamp
opening 3b.
As shown in Fig. 3, the mutually adjacent clamp limbs 2b; 2a of the
two clamps la; lb have a mutually engaging conical elevation 30 and conical
depression 31, which are coaxial with the axis of rotation 6, respectively.
The
conical elevation 30 is provided here at the surface of the upper clamp la,
which
adjoins the lower clamp lb, whereas the conical depression 31, which is
complementary thereto, is provided at the surface of the lower clamp lb
adjoining
the upper clamp I a. The mutually contacting surfaces of the conical elevation
30
and the conical depression 31 respectively may be roughened, so that a
relative
rotation of the two clamps 1 a; lb about the axis of rotation 6 is prevented
when the
blocking means 8 are tightened. Moreover, at the axially external outlets, the
boreholes 4, passing through the two clamps la; lb, comprise borehole segments
29, each of which has a concave, spherical zone-like surface 33. Configured
complementarily to these borehole segments 29 is the head 18 at the second end
15 of the shaft 7 as well as an intermediate piece 28, which is disposed
coaxially
between the nut 17 and the upper clamp I a, that is, the head 18 has a convex
spherical zone-like surface 32 directed towards the lower clamp lb and the
intermediate piece 28 also has a convex, spherical zone-like surface 32, which
is
directed against the upper clamp 1 b.
The locking-in-position pins 26 at the upper clamp 1 a are also
shown in Fig. 3. These locking-in-position pins 26 can be screwed by means of
a
threaded connection into boreholes 25, which are parallel to the axis of
rotation 6
in the inner clamp limb 2b of the upper clamp I a and can be adjusted so that
they
limit the pressing together of the clamp openings 3a; 3b at the upper clamp
la.
For this purpose, the locking-in-position pins 26 are screwed in, until the
front end
34a of the first locking-in-position pin 26a is in contact with the surface of
the
middle clamp limb 2c, which is adjacent to the inner clamp limb 2b, and the
front
end 34b of the second locking-in-position pin 26b is in contact with the
surface of
the outer clamp limb 2a, which is adjacent to the middle clamp limb 2c.
7
